package org.diffgenova;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.widget.Toast;

public class DataBaseHelper extends SQLiteOpenHelper {
    
    // The Android's default system path of your application database.
    private static String DB_PATH = "/data/data/org.diffgenova/databases/";
    
    private static String DB_NAME = "diff";
    
    private static int DB_VERSION = 2;
    
    private SQLiteDatabase myDataBase;
    
    private final Context myContext;
    
    public DataBaseHelper(Context context) {
        
        super(context, DB_NAME, null, 1);
        this.myContext = context;
    }
    
    /**
     * Creates a empty database on the system and rewrites it with your own
     * database.
     * */
    public void createDataBase() throws IOException {
        boolean dbExist = checkDataBase();
        
        if (dbExist) {
            // do nothing - database already exist
        } else {
            
            // By calling this method and empty database will be created into
            // the default system path
            // of your application so we are gonna be able to overwrite that
            // database with our database.
            this.getReadableDatabase();
            
            try {
                
                copyDataBase();
                
            } catch (IOException e) {
                
                throw new Error("Error copying database");
                
            }
        }
        
    }
    
    /**
     * Check if the database already exist to avoid re-copying the file each
     * time you open the application.
     * 
     * @return true if it exists, false if it doesn't
     */
    private boolean checkDataBase() {
        
        boolean dbOK = false;
        
        SQLiteDatabase checkDB = null;
        
        try {
            String myPath = DB_PATH + DB_NAME;
            checkDB = SQLiteDatabase.openDatabase(myPath, null,
                                                  SQLiteDatabase.OPEN_READONLY);
            Cursor c = checkDB.rawQuery("PRAGMA user_version", null);
            c.moveToFirst();
            if (c.getInt(0) == DB_VERSION)
                dbOK = true;
            
        } catch (SQLiteException e) {
            
            // database does't exist yet.
            
        }
        
        if (checkDB != null) {
            
            checkDB.close();
            
        }
        
        return dbOK;
    }
    
    /**
     * Copies your database from your local assets-folder to the just created
     * empty database in the system folder, from where it can be accessed and
     * handled. This is done by transfering bytestream.
     * */
    private void copyDataBase() throws IOException {
        
        // Open your local db as the input stream
        InputStream myInput = myContext.getAssets().open(DB_NAME);
        
        // Path to the just created empty db
        String outFileName = DB_PATH + DB_NAME;
        
        // Open the empty db as the output stream
        OutputStream myOutput = new FileOutputStream(outFileName);
        
        // transfer bytes from the inputfile to the outputfile
        byte[] buffer = new byte[1024];
        int length;
        while ((length = myInput.read(buffer)) > 0) {
            myOutput.write(buffer, 0, length);
        }
        
        // Close the streams
        myOutput.flush();
        myOutput.close();
        myInput.close();
        
    }
    
    public void openDataBase() {
        
        // Open the database
        String myPath = DB_PATH + DB_NAME;
        myDataBase = SQLiteDatabase.openDatabase(myPath, null,
                                                 SQLiteDatabase.OPEN_READONLY);
        
    }
    
    @Override
    public synchronized void close() {
        
        if (myDataBase != null)
            myDataBase.close();
        
        super.close();
        
    }
    
    @Override
    public void onCreate(SQLiteDatabase db) {
        
    }
    
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        if (oldVersion != DB_VERSION) {
            try {
                copyDataBase();
            } catch (IOException e) {
                Toast.makeText(myContext, "Unable to upgrade DB", Toast.LENGTH_LONG);
                e.printStackTrace();
            }
        }
    }
    
    public String getCat(String rifiuto) {
        Cursor cursor = myDataBase.rawQuery("select categoria.descrizione from rifiuto, categoria where rifiuto.categoria = categoria._id and rifiuto.descrizione = ?",
                                            new String[] {
                                                rifiuto
                                            });
        cursor.moveToFirst();
        String cat = cursor.getString(0);
        cursor.close();
        return cat;
    }
    
    public Cursor getRifiuti() {
        Cursor cursor = myDataBase.rawQuery(
                                            "select rifiuto.descrizione rifiutodes, categoria._id, categoria.descrizione categoriades, categoria.icona iconades from rifiuto, categoria where rifiuto.categoria = categoria._id order by rifiuto.descrizione",
                                            null);
        return cursor;
    }
    
    public Cursor getRifiuti(String searchString) {
        if (searchString != null && searchString.length() > 0) {
            String sql = "select rifiuto.descrizione rifiutodes, categoria._id, categoria.descrizione categoriades, categoria.icona iconades from rifiuto, categoria where rifiuto.categoria = categoria._id and rifiuto.descrizione like '%"
                    + searchString + "%' order by rifiuto.descrizione";
            Cursor cursor = myDataBase.rawQuery(
                                                sql,
                                                null);
            return cursor;
        } else {
            return getRifiuti();
        }
    }
    
    public Cursor getCategorie(String searchString) {
        if (searchString != null && searchString.length() > 0) {
            String sql = "select rifiuto.descrizione rifiutodes, categoria._id, categoria.descrizione categoriades, categoria.icona iconades from rifiuto, categoria where rifiuto.categoria = categoria._id and categoria.descrizione like '%"
                    + searchString + "%' order by categoria.descrizione";
            Cursor cursor = myDataBase.rawQuery(
                                                sql,
                                                null);
            return cursor;
        } else {
            return getRifiuti();
        }
    }
    
    public Cursor getCategorie() {
        Cursor cursor = myDataBase.rawQuery(
                                            "select categoria._id, categoria.descrizione categoriades, categoria.icona iconades from categoria order by categoria.descrizione",
                                            null);
        return cursor;
    }
    
}
